/*
 * $Id: JSONValue.java,v 1.1 2006/04/15 14:37:04 platform Exp $
 * Created on 2006-4-15
 */
package org.json.simple;

import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import java.io.StringWriter;
import java.io.Writer;
import java.util.Collection;
// import java.util.List;
import java.util.Map;

import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;

/**
 * @author FangYidong<fangyidong@yahoo.com.cn>
 */
public class JSONValue {
	/**
	 * Parse JSON text into java object from the input source. Please use
	 * parseWithException() if you don't want to ignore the exception.
	 * 
	 * @see org.json.simple.parser.JSONParser#parse(Reader)
	 * @see #parseWithException(Reader)
	 * 
	 * @param in
	 * @return Instance of the following: org.json.simple.JSONObject,
	 *         org.json.simple.JSONArray, java.lang.String, java.lang.Number,
	 *         java.lang.Boolean, null
	 * 
	 * @deprecated this method may throw an {@code Error} instead of returning
	 *             {@code null}; please use
	 *             {@link JSONValue#parseWithException(Reader)} instead
	 */
	public static Object parse(Reader in) {
		try {
			JSONParser parser = new JSONParser();
			return parser.parse(in);
		} catch (Exception e) {
			return null;
		}
	}

	/**
	 * Parse JSON text into java object from the given string. Please use
	 * parseWithException() if you don't want to ignore the exception.
	 * 
	 * @see org.json.simple.parser.JSONParser#parse(Reader)
	 * @see #parseWithException(Reader)
	 * 
	 * @param s
	 * @return Instance of the following: org.json.simple.JSONObject,
	 *         org.json.simple.JSONArray, java.lang.String, java.lang.Number,
	 *         java.lang.Boolean, null
	 * 
	 * @deprecated this method may throw an {@code Error} instead of returning
	 *             {@code null}; please use
	 *             {@link JSONValue#parseWithException(String)} instead
	 */
	public static Object parse(String s) {
		StringReader in = new StringReader(s);
		return parse(in);
	}

	/**
	 * Parse JSON text into java object from the input source.
	 * 
	 * @see org.json.simple.parser.JSONParser
	 * 
	 * @param in
	 * @return Instance of the following: org.json.simple.JSONObject,
	 *         org.json.simple.JSONArray, java.lang.String, java.lang.Number,
	 *         java.lang.Boolean, null
	 * 
	 * @throws IOException
	 * @throws ParseException
	 */
	public static Object parseWithException(Reader in) throws IOException, ParseException {
		JSONParser parser = new JSONParser();
		return parser.parse(in);
	}

	public static Object parseWithException(String s) throws ParseException {
		JSONParser parser = new JSONParser();
		return parser.parse(s);
	}

	/**
	 * Encode an object into JSON text and write it to out.
	 * <p>
	 * If this object is a Map or a List, and it's also a JSONStreamAware or a
	 * JSONAware, JSONStreamAware or JSONAware will be considered firstly.
	 * <p>
	 * DO NOT call this method from writeJSONString(Writer) of a class that
	 * implements both JSONStreamAware and (Map or List) with "this" as the
	 * first parameter, use JSONObject.writeJSONString(Map, Writer) or
	 * JSONArray.writeJSONString(List, Writer) instead.
	 * 
	 * @see org.json.simple.JSONObject#writeJSONString(Map, Writer)
	 * @see org.json.simple.JSONArray#writeJSONString(List, Writer)
	 * 
	 * @param value
	 * @param writer
	 */
	@SuppressWarnings("rawtypes")
	public static void writeJSONString(Object value, Writer out) throws IOException {
		if (value == null) {
			out.write("null");
			return;
		}

		if (value instanceof String) {
			out.write('\"');
			out.write(escape((String) value));
			out.write('\"');
			return;
		}

		if (value instanceof Double) {
			if (((Double) value).isInfinite() || ((Double) value).isNaN())
				out.write("null");
			else
				out.write(value.toString());
			return;
		}

		if (value instanceof Float) {
			if (((Float) value).isInfinite() || ((Float) value).isNaN())
				out.write("null");
			else
				out.write(value.toString());
			return;
		}

		if (value instanceof Number) {
			out.write(value.toString());
			return;
		}

		if (value instanceof Boolean) {
			out.write(value.toString());
			return;
		}

		if ((value instanceof JSONStreamAware)) {
			((JSONStreamAware) value).writeJSONString(out);
			return;
		}

		if ((value instanceof JSONAware)) {
			out.write(((JSONAware) value).toJSONString());
			return;
		}

		if (value instanceof Map) {
			JSONObject.writeJSONString((Map) value, out);
			return;
		}

		if (value instanceof Collection) {
			JSONArray.writeJSONString((Collection) value, out);
			return;
		}

		if (value instanceof byte[]) {
			JSONArray.writeJSONString((byte[]) value, out);
			return;
		}

		if (value instanceof short[]) {
			JSONArray.writeJSONString((short[]) value, out);
			return;
		}

		if (value instanceof int[]) {
			JSONArray.writeJSONString((int[]) value, out);
			return;
		}

		if (value instanceof long[]) {
			JSONArray.writeJSONString((long[]) value, out);
			return;
		}

		if (value instanceof float[]) {
			JSONArray.writeJSONString((float[]) value, out);
			return;
		}

		if (value instanceof double[]) {
			JSONArray.writeJSONString((double[]) value, out);
			return;
		}

		if (value instanceof boolean[]) {
			JSONArray.writeJSONString((boolean[]) value, out);
			return;
		}

		if (value instanceof char[]) {
			JSONArray.writeJSONString((char[]) value, out);
			return;
		}

		if (value instanceof Object[]) {
			JSONArray.writeJSONString((Object[]) value, out);
			return;
		}

		out.write(value.toString());
	}

	/**
	 * Convert an object to JSON text.
	 * <p>
	 * If this object is a Map or a List, and it's also a JSONAware, JSONAware
	 * will be considered firstly.
	 * <p>
	 * DO NOT call this method from toJSONString() of a class that implements
	 * both JSONAware and Map or List with "this" as the parameter, use
	 * JSONObject.toJSONString(Map) or JSONArray.toJSONString(List) instead.
	 * 
	 * @see org.json.simple.JSONObject#toJSONString(Map)
	 * @see org.json.simple.JSONArray#toJSONString(List)
	 * 
	 * @param value
	 * @return JSON text, or "null" if value is null or it's an NaN or an INF
	 *         number.
	 */
	public static String toJSONString(Object value) {
		final StringWriter writer = new StringWriter();

		try {
			writeJSONString(value, writer);
			return writer.toString();
		} catch (IOException e) {
			// This should never happen for a StringWriter
			throw new RuntimeException(e);
		}
	}

	/**
	 * Escape quotes, \, /, \r, \n, \b, \f, \t and other control characters
	 * (U+0000 through U+001F).
	 * 
	 * @param s
	 * @return
	 */
	public static String escape(String s) {
		if (s == null)
			return null;
		StringBuffer sb = new StringBuffer();
		escape(s, sb);
		return sb.toString();
	}

	/**
	 * @param s
	 *            - Must not be null.
	 * @param sb
	 */
	static void escape(String s, StringBuffer sb) {
		final int len = s.length();
		for (int i = 0; i < len; i++) {
			char ch = s.charAt(i);
			switch (ch) {
			case '"':
				sb.append("\\\"");
				break;
			case '\\':
				sb.append("\\\\");
				break;
			case '\b':
				sb.append("\\b");
				break;
			case '\f':
				sb.append("\\f");
				break;
			case '\n':
				sb.append("\\n");
				break;
			case '\r':
				sb.append("\\r");
				break;
			case '\t':
				sb.append("\\t");
				break;
			case '/':
				sb.append("\\/");
				break;
			default:
				// Reference: http://www.unicode.org/versions/Unicode5.1.0/
				if ((ch >= '\u0000' && ch <= '\u001F') || (ch >= '\u007F' && ch <= '\u009F')
						|| (ch >= '\u2000' && ch <= '\u20FF')) {
					String ss = Integer.toHexString(ch);
					sb.append("\\u");
					for (int k = 0; k < 4 - ss.length(); k++) {
						sb.append('0');
					}
					sb.append(ss.toUpperCase());
				} else {
					sb.append(ch);
				}
			}
		} // for
	}

}
